CN109475413B

CN109475413B - Compact crimping device

Info

Publication number: CN109475413B
Application number: CN201780044281.2A
Authority: CN
Inventors: T·萨尔; G·瑞恩伯格
Original assignee: Edwards Lifesciences Corp
Current assignee: Edwards Lifesciences Corp
Priority date: 2016-06-24
Filing date: 2017-06-23
Publication date: 2021-09-03
Anticipated expiration: 2037-06-23
Also published as: CR20180577A; EP3474779A1; US20230111584A1; EP3474779B1; US11951025B2; US20200345526A1; EP3474779A4; US10716691B2; US11523923B2; EP4353202A2; US20170367858A1; CA3025970A1; US11510794B2; CN109475413A; WO2017223486A1; SG11201810582QA; US20210106446A1; CN113616382A

Abstract

A compact crimping mechanism well suited for use with devices such as stented prosthetic heart valves. The crimping mechanism includes a plurality of jaws configured to move in unison inward toward the crimping axis to reduce the size of a crimped iris around the stented valve. The rotating cam acts on the jaws and moves them inwardly. A plurality of cartesian guide elements cooperate with the jaws to distribute forces within the crimping mechanism. The guide member is located between the crimping jaws and the outer housing and is constrained by the outer housing to move along a line tangent to a circle centered on the crimping axis. The guide members engage at least some of the crimping jaws while the remaining crimping jaws are in meshing engagement for synchronous movement. The actuating mechanism includes a lead screw, a carriage assembly, and a linkage for rotating the cam with substantial torque.

Description

Compact crimping device

Technical Field

The present invention relates to crimping devices, and more particularly, to compact devices for crimping devices (e.g., stented prosthetic valves, such as heart valves, from large to small diameters).

Background

Stents are generally cylindrical prostheses that are introduced into the lumen of a body vessel by a catheterization technique. The stent may be self-expanding or balloon expandable. Balloon expandable stents are typically crimped from an initial large diameter to a smaller diameter prior to advancement to a treatment site within the body. Prior to crimping, a balloon expandable stent is typically placed over the expandable balloon on the catheter shaft. Where the stent is manufactured at its fully crimped diameter, the stent is expanded on a balloon and then crimped. To ensure safety, the crimping process should be performed in a sterile environment. For many years, attempts have been made to crimp stents on balloons during surgery in a sterile field. However, most stents are now "pre-crimped" onto a suitable balloon at the factory and then given to the physician ready for use.

One example of a crimping device for stents based on movable jaws is disclosed in U.S. patent No.6,360,577 to Austin. The crimping device uses an inclined plane that forces the jaws to move from an open position to a closed position. One major disadvantage is that the length of the inclined plane is given by the full circle (360 °) divided by the number of jaws that are actuated. A long inclined plane is preferred for reducing circumferential resistance or friction, but in order to achieve a smooth hole for crimping a stent, a large number of jaws are required, which means a shorter inclined plane, less leverage and higher friction. Thus, the effectiveness of this type of device is substantially limited and may only be practical for stents having a diameter of 1.5 to 4.0mm in its expanded size.

In recent years, various prosthetic valves have been developed in which a valve structure is mounted on a stent and then delivered to a treatment site by a percutaneous catheterization technique. The diameter of a prosthetic valve is typically much larger relative to a coronary stent. While typical stented coronary stents have diameters of only 1.5 to 4.0mm, stented prosthetic valve diameters will typically be in the range of about 19 to 29mm, at least 5 times greater.

Another difference is that the coronary stent is a separate metal device that can be crimped onto the balloon prior to encapsulation. For prosthetic valves, the stent serves as a scaffold that holds the valve structure, which is typically made of a biological material (such as a pericardial valve or harvested valve). For improved function after deployment, it is often desirable to encapsulate such valves in a preservation solution in an open (i.e., expanded) state. Therefore, it is necessary to crimp the valve in the operating room a few minutes before implantation, thereby eliminating pre-crimping on the balloon by the manufacturer.

Due to the unique crimping requirements of stent-based prosthetic valves, it has been found that existing crimping devices configured for use with coronary stents are not suitable for use with stent-based prosthetic valves. Additionally, as noted above, existing crimping mechanisms suffer from various drawbacks that limit their ability to be adapted for use with stent-based prosthetic valves. Due to the deficiencies associated with the prior art crimping, a new crimping device is described in commonly owned U.S. patent No.6,730,118 to Spenser et al, which relates to a crimping device adapted to crimp a prosthetic valve as part of an implantation procedure.

Another version of a prosthetic heart valve crimper is sold by Machine Solutions Inc. The HV200 is a disposable crimper that uses multiple pivoting segments to crimp a percutaneous heart valve. Machine solution crimpers are also disclosed in two U.S. patent nos. 6,629,350 and 6,925,847 to Motsenbocker. These crimping devices are based on rotation about a pivot pin to create a radially compressed section. Unfortunately, the pivoting design tends to concentrate stress in certain areas of the various sections and in the mechanisms used to pivot the sections. Moreover, the user must apply a significant amount of force to close the crimper hole around the relatively large percutaneous heart valve.

U.S. patent No.7,530,253 discloses a crimping mechanism for a prosthetic heart valve having linearly moving jaws capable of crimping a relatively large size valve to a small delivery size but also of a relatively large size.

Although the heart valve crimping techniques available to date provide improvements over existing stent crimper techniques, it has been found that there remains a need for more effective devices. It is desirable that such a device be capable of crimping a valve from a diameter of about 29mm to a crimped size of about 6mm without requiring excessive force and without inducing high mechanical stress within the device. It is also desirable that such devices be simple to use and relatively inexpensive to manufacture. It is also desirable that such devices be sterile and suitable for manual operation in a catheter laboratory or operating room. The present invention addresses this need.

Disclosure of Invention

The present invention provides a method and apparatus for crimping an expandable prosthetic heart valve having a support frame and a stent. The crimping mechanism includes a plurality of jaws configured for coordinated inward movement toward the crimping axis to reduce the size of the crimped iris around the stented valve. The rotating cam acts on the jaws and displaces them inwardly. A plurality of cartesian guide elements cooperate with the jaws to distribute forces within the crimping mechanism. The guide member is located between the crimping jaws and the outer housing and is constrained by the outer housing to move along a line tangent to a circle centered on the crimping axis. The guide members engage at least some of the crimping jaws while the remaining crimping jaws are in meshing engagement for synchronous movement. The actuating mechanism includes a lead screw, a carriage assembly, and a linkage for rotating the cam with substantial torque.

In one embodiment, a prosthetic valve crimping device capable of reducing the diameter of an expandable prosthetic stented valve includes a plurality of crimping jaws meshingly engaged and circumferentially arranged about a crimping aperture having a central crimping axis, each crimping jaw having an inner crimping wedge. The rotating cam acts on the crimping jaws and displaces them substantially radially inwardly, while the stationary outer housing contains the cam and the crimping jaws. Finally, a plurality of guide elements are each constrained by a fixed groove in the outer housing to move between a first position and a second position along a line tangent to a circle about the central axis, wherein the guide elements move at least some of the crimping jaws along the line such that all of the crimping wedges of the crimping jaws translate inwardly along a radial line toward the crimping axis.

In one aspect, the crimping wedge is made of a different material than the remaining crimping jaws. The guide member may be a separate member from the crimping jaws. Preferably, the guide element is rigidly coupled to at least some of the crimping jaws by being integrally formed with or fastened to at least some of the crimping jaws.

Advantageously, the crimping jaws each comprise a pair of travel blocks on the cam sides and an assembly of one of the crimping wedges that extends across the central aperture in the cam. The cam may comprise two discs with helical cam grooves, the discs acting on cams fixed to each side run and extending axially inwardly into the cam grooves. Also, the cam plates may each have a cam rod extending radially outward therefrom that is driven by a carriage assembly on the lead screw. Preferably, the link between the cam lever and the carriage assembly increases the torque applied to the cam when the carriage assembly reaches the opposite ends of the lead screw.

In a second aspect, the present application discloses a prosthetic valve crimping device capable of reducing the diameter of an expandable prosthetic stented valve. The apparatus has a plurality of crimping jaws meshingly engaged and circumferentially arranged about a crimping aperture having a central crimping axis, wherein the crimping jaws each include an assembly of a pair of spaced apart traveling blocks and a radially inner crimping wedge extending therebetween. A rotary cam acts on the crimping jaws and displaces them generally radially inwardly, the cam comprising two discs having helical cam grooves, the discs acting on a cam fixed to each side travel block and extending axially inwardly into the cam grooves. The stationary outer housing contains the cam and crimping jaws and a lower actuating mechanism including a lead screw and carriage assembly coupled to rotate the cam. A pair of travel blocks of at least some of the crimping jaws are constrained by a fixed groove in the outer housing to move along a line tangent to a circle about the central axis such that all of the crimping wedges of the crimping jaws translate inwardly along a radial line toward the crimping axis.

In the apparatus of the second aspect, the cam plates may each have a cam rod extending radially outwardly therefrom, the cam rod being driven by a carriage assembly on the lead screw via a link between the cam rod and the carriage assembly, the link increasing the torque applied to the cam when the carriage assembly reaches opposite ends of the lead screw. Furthermore, a drive motor may be provided to actuate the lead screw. Also, the crimping wedge may be made of a different material than the remaining crimping jaws.

The device of the second aspect may further comprise a plurality of guide elements, each constrained by a fixed groove in the outer housing, to move between the first position and the second position along a line tangent to a circle about the central axis. The guide element moves at least some of the crimping jaws along the wire such that all of the crimping wedges of the crimping jaws translate inwardly along the radial line toward the crimping axis.

In one embodiment, half the number of guide elements act as crimping jaws, so that some of the crimping jaws are driven and others are followers. Preferably, the guide element is rigidly connected to the travelling block of the half crimping jaws by being formed integrally with or fastened to the half crimping jaws.

In either aspect, each guide element may comprise an irregular diamond shaped rectilinear plate having four vertices and straight sides therebetween with a notch on one side adjacent one of the vertices and one of the vertices of each rectilinear plate fits closely within the notch on the adjacent guide member when the guide element is displaced along the line to the second position, and this manner of nested contact between all guide elements provides a positive stop for further inward movement of the crimping mechanism.

Drawings

FIG. 1A is a perspective view of an exemplary prosthetic heart valve having an expandable support frame and a plurality of flexible leaflets therein;

FIG. 1B is a side view of the prosthetic heart valve of FIG. 1A crimped to a reduced diameter around a balloon catheter;

FIGS. 2A and 2B are partial cross-sectional views of the present crimping mechanism in both an open crimping jaw position and a closed crimping jaw position;

FIG. 3A is an exploded perspective view showing components of an exemplary crimping mechanism;

FIG. 3B is a partially exploded perspective view of an exemplary crimping mechanism having an assembled movable crimping jaw combination, while FIG. 3C is a perspective view of an exemplary cam forming a portion of the crimping jaw combination;

FIG. 4 is an elevational view of a central cam forming part of the movable crimping jaw combination;

FIGS. 5A and 5B are different perspective views of one of the crimping jaws showing the inner cam follower and FIG. 5C is a front view;

FIG. 6 is a perspective view of a movable crimping jaw combination including a cam, crimping jaws and a plurality of Cartesian guide elements;

FIGS. 7A and 7B are front views of the internal crimping mechanism in both the open crimping jaw position and the closed crimping jaw position showing the central cam and crimping jaws assembled on the internal crimping mechanism;

FIG. 8 is an elevation view of an interior face of one half of the outer housing of the exemplary crimping mechanism showing a fixed guide channel on the interior face;

FIG. 9A is a view of a plurality of Cartesian guide elements arranged in space in the same manner as when interacting with the outer housing of the crimping mechanism of FIG. 8, while FIG. 9B is a perspective view of a single Cartesian guide element;

FIG. 10A is an elevation view of the inner face of the outer housing of the crimping mechanism showing the position of the guide element on the inner face when in a radially outward position, and FIG. 10B is a similar view showing the guide element in a radially inward position;

FIGS. 11A and 11B are elevational views similar to FIGS. 7A and 7B and further showing guide members interacting with the crimping jaws;

11C and 11D are partial cross-sectional views of FIGS. 11A and 11B showing the interaction of only one guide member with three crimping jaws;

FIG. 11E separates a center one of the crimping jaws from FIGS. 11C and 11D to show relative and absolute movement thereof;

FIGS. 12A and 12B are schematic perspective views of an alternative embodiment of the present crimping mechanism in both an open crimping jaw position and a closed crimping jaw position, which is very similar to the crimping mechanism of FIGS. 1A-11E but with modified guide elements;

13A-13C are several views of another embodiment of a crimping mechanism of the present application that is similar to the crimping mechanism shown in FIGS. 1A-12B but with fewer guide elements;

14A-14C are partial front elevational views of the crimping mechanism of FIGS. 13A-13C in both the open crimping jaw position and the closed crimping jaw position;

15A-15B are front elevational views of yet another crimping mechanism of the present application that utilizes a compressible sleeve, shown in both an open and crimped state;

16A-16B are front elevational views of a crimping mechanism having a compressible sleeve with a front cover removed to show the inner components in the positions of FIGS. 15A and 15B, respectively;

FIG. 17 is an exploded view of the crimping mechanism with compressible jaws;

FIG. 18 is a cut-away perspective view of a crimping mechanism having compressible jaws;

FIGS. 19A-19B are perspective cutaway views of a crimping mechanism having compressible jaws illustrating movement of a compression assembly;

FIGS. 20A-20C are perspective and cross-sectional views of a series of progressively larger sized crimping mechanisms, each having compressible jaws;

21A-21B are schematic elevational views of yet another crimping mechanism of the present application that utilizes compressible jaws; and

fig. 22A is a perspective view of an alternative crimping mechanism having a modified actuating mechanism and outer housing shown in phantom, while fig. 22B shows the crimping mechanism from a different perspective and without the outer housing, and fig. 22C shows a number of internal components including an exploded crimping jaw.

Detailed Description

The present invention provides an improved crimper for a stent or prosthetic valve. The particularly advantageous features of the present crimper enable the diameter of relatively large stents or prosthetic valves to be reduced in conjunction with small-sized crimpers that generate high crimping forces to result in small final diameters. The crimper is particularly useful for crimping prosthetic heart valves having a significantly larger expanded diameter than most stents currently in use. According to Chessa et al, Palmaz-Genesis XD stents (Cordis J & J Interactive Systems Co. (Congtie J & J Interventional Systems Co.)) were designed for an expansion range of 10-18mm and were considered large or very large stents (see "Results and Mid-long term Follow-up of Stent Implantation for Natural and Current coronary diagnosis of the Aorta" for stenting stents for treatment of primary and Recurrent aortic stenosis ", published online in European journal of the Heart on 26.9.2005, Vol.26, Vol.24, p.2728. 2732). The most commonly used stents are significantly smaller, in the range of 3-6 mm. Crimpers used with these stents have proven insufficient to reduce the size of even larger prosthetic valves (e.g., stented prosthetic heart valves). Conversely, aspects of the present crimper may also be applicable to crimping stents, but certain features described herein also make it particularly suitable for crimping large diameter stents, stent grafts, and prosthetic valves.

The term "stented valve" as used herein refers to prosthetic valves for implantation, primarily to prosthetic heart valves, but venous valves and the like are also contemplated. Stented valves have a support frame or stent that provides the primary structural support in its expanded state. Such support frames are generally tubular when expanded and may be expanded using balloons or by their own inherent elasticity (i.e., self-expanding) or by mechanical means. An exemplary stented valve is shown with respect to fig. 1A and 1B, but the invention can also be used to crimp other such prosthetic valves.

Fig. 1A shows an exemplary balloon-expandable prosthetic heart valve 20 having an inflow end 22 and an outflow end 24. The valve includes an outer stent or support frame 26 that supports a plurality of flexible leaflets 28 therein. FIG. 1A shows the valve 20 in its expanded or operational shape, wherein the support frame 26 generally defines a lumen having a diameter D_maxAnd three leaflets 28 attached to the support frame extend into the cylindrical space defined therein to meet each otherAnd (4) firmly fixing. In the exemplary valve 20, three separate leaflets 28 are each secured to the support frame 26 and to the other two leaflets along their adjacent lines or commissures. Of course, whole bioprosthetic valves, such as porcine valves, may also be used. In this sense, "leaflet" refers to either a separate leaflet or a leaflet within the entire xenograft valve.

Fig. 1B shows the valve 20 mounted on a balloon 30 prior to inflation. Crimped outer diameter of valve 20D_minAnd (4) showing. Balloon 30 is typically mounted on the end of catheter 32 that is guided over steerable wire 34 to the implantation site.

More details regarding exemplary prosthetic heart valves of a similar type may be found in U.S. Pat. No.6,730,118 and U.S. patent publication No.2014/0343671, which are expressly incorporated herein by reference. In addition, available from Edwards Lifesciences, Inc. of Ulwan, Calif

The heart valve family is balloon expandable prosthetic heart valves of similar nature, the construction of which is also expressly incorporated herein by reference.

U.S. patent No.7,530,253 (expressly incorporated herein by reference) discloses a crimping mechanism for a prosthetic heart valve having the ability to crimp a relatively large sized valve to a small delivery size. However, the mechanism in the' 253 patent is relatively large because of the high leverage required to crimp large diameter valves. In contrast, the crimper mechanism disclosed herein uses cartesian movement guide elements to generate radial jaw movement near the central aperture. Thus, the size of the crimping jaws is significantly reduced and the stiffness (or ability to withstand higher crimping forces) of the jaws is increased.

The crimper mechanism of the present application is effective to size prosthetic valves from up to 30mm (D)_max) Reduce to 6mm (D)_min). Prosthetic heart valve sizes are generally anywhere between 20mm up to about 30 mm. Thus, the minimum amount of size reduction is about 14mm, and the mostA large amount is about 24 mm. In contrast, a typical coronary stent has an expanded diameter of between about 3-6mm and is crimped to a minimum diameter of between about 1.5-2mm for a total maximum size reduction of about 4 mm. To distinguish from conventional stent crimpers, the present invention provides a diameter reduction of at least 10mm, and preferably at least 20 mm. Because the diametrically opposed jaws act against each other to reduce the size of the prosthetic valve, each jaw crimps the valve half the distance the overall diameter is reduced. This means that each jaw is moved radially inwardly by at least 5mm, and more preferably by at least 10 mm.

Referring now to fig. 2A and 2B, a preferred embodiment of an improved prosthetic heart valve crimping mechanism 40 is shown. The crimping mechanism 40 includes an outer housing 42, the outer housing 42 enclosing a plurality of crimping jaws 44 arranged about a central crimping axis 46. As will be described, there are preferably 12 crimping jaws 44, but other numbers of jaws are possible. The jaws 44 are initially shown in fig. 2A as being retracted outwardly so as to not be visible within the receiving aperture 48, the receiving aperture 48 being sized large enough to receive the expanded heart valve 20 as shown in fig. 1B. Fig. 2B shows the crimping jaws 44 displaced radially inwardly in a coordinated manner to form a crimped iris 50 defined by the combined inner surfaces of the jaw assemblies. The crimped iris 50 has a minimum diameter small enough to fully crimp the heart valve 20 onto the balloon 30. Although not shown, the crimping operation includes placing the expanded heart valve 20 around the balloon 30 prior to inserting the assembly into the orifice 48 and actuating the crimping jaws 44.

In both fig. 2A and 2B, a lower portion of the outer housing 42 is cut away to expose a portion of the actuation mechanism therein. Specifically, a relatively large diameter, horizontally oriented lead screw 52 is journaled for rotation on either side of the housing 42 and perpendicular to the crimp axis 46. Although not shown, it is desirable that the motor in the lower portion of the housing 42 be connected via a power transmission to drive the lead screw 52 and increase the applied force. Alternatively, one or both ends of the lead screw 52 extend outwardly from the housing 42 and terminate in a nut or other such keyed element. The lead screw 52 can be manually rotated about its axis by inserting a crank or key into one end of the lead screw. An internally threaded carriage 54 travels back and forth along the lead screw 52 as the lead screw 52 rotates. The carriage 54 features a stub shaft 56 extending from one side that is retained within a large slot 58 formed in a lever arm 60 of a cam 62 (see fig. 3A and 3B) to prevent the carriage from rotating with the lead screw.

More details of the interaction between the cam 62 and the crimping jaws 44 will be explained more fully below. However, as shown in fig. 2A and 2B, rotation of the lead screw 52 advances the carriage 54 from right to left, and the carriage 54 in turn interacts with the lever arm slot 58 and rotates the cam 62 Clockwise (CW). Rotating the cam 62 in this manner causes the jaws 44 to shift from their radially outward position to their radially inward position, thereby crimping the heart valve 20.

Fig. 3A is an exploded perspective view illustrating the internal components of an exemplary crimping mechanism 40. The outer housing 42 comprises two profiled halves which together provide a bearing seat for the lead screw 52. Although only the inner face of one of the two housing halves is shown, both housing halves include a plurality of linear guide channels 64 formed in their inner faces and disposed tangentially around the receiving aperture 48 in a spoke-like manner. The two halves of the outer housing 42 sandwich the crimping jaw assembly 66 therebetween.

Fig. 3B is a partially exploded perspective view of crimping mechanism 20 showing crimping jaw assembly 66 and one half of outer housing 42 with its guide channel 64. Crimping jaw assembly 66 has a generally cylindrical profile that fits closely within a similarly shaped upper portion of outer housing 42 and is centered along crimping axis 46. In addition to the lead screw 52 and carriage 54, the crimping jaw assembly 66 is also comprised of movable components within the crimping mechanism 40. Referring also to FIG. 3A, crimping jaw assembly 66 comprises an axial sandwich of elements, intermediate cam 62. Crimping jaws 44 flank cam 62 and a plurality of cartesian guide elements 70 are disposed outboard of crimping jaws 44. Further, crimping jaw assembly 66 is securely located within both halves of housing 42, but may also rotate therein.

To understand the interaction between the moving parts of crimping jaw assembly 66, it must start at cam 62 and move axially outward. The cam 62 is rotated by the lead screw 52 and carriage 54 to create the motive force for the crimping jaw assembly 66. Typically, rotation of the cam 62 initiates movement of all other components, however, as will be described below, the physical interaction and guided contact between the components creates an additional reaction force that distributes the force from the cam.

Fig. 3C is a perspective view of an exemplary cam 62, the cam 62 including a pair of parallel annular disks 72, the annular disks 72 being connected on their inner circular edges by an annular hub 74. A plurality of axially oriented rollers 76 are journalled for rotation between the two discs 72 and are circumferentially distributed in an annular space 78, the annular space 78 being defined radially outwardly of the hub 74. Each roller 76 projects slightly outwardly from the outer edge of the disc 72 for contact with the outer housing 42 to facilitate rotation therein and provide stability to the crimping operation. As also shown in FIG. 4, each annular disc 72 includes a series of arcuate cam slots 80 formed therein that are generally curved from their radially inner portions to their radially outer edges. Each cam groove 80 is curved so as to project radially outward. The arcuate cam slots 80 on both discs 72 are aligned and have the same shape such that the cam slots 80 extend radially outward in a Clockwise (CW) direction (i.e., fig. 4) when viewing the outer face of one disc and extend radially outward in a counterclockwise (CCW) direction when viewing the outer face of the other disc.

In the illustrated embodiment, there are twelve cam slots 80 that nest relatively closely with one another around each disc 72. Two aligned slots 80 in each of the two discs 72 act on one jaw 44, and thus there are twelve jaws 44 in the preferred embodiment. It will be appreciated that the number of crimping jaws 44, and thus cam slots 80, may be modified, but is preferably between 8-16.

As shown in fig. 5A-5C, each crimping jaw 44 includes a radially inner crimping wedge 82, radially inner crimping wedge 82 connecting a pair of axially spaced apart generally triangular outer travel blocks 84. The front view of fig. 5C shows that the travel blocks each span an angle theta that varies depending on the number of jaws 44 used, and is preferably 30 deg. in the case of 12 jaws. When the jaws 44 are assembled with the cam 62, as shown in fig. 6, the jaws 44 are in their radially outward position and the crimping wedge 82 is positioned within a central aperture defined within the annular hub 74 of the cam 62. The inner surface of the crimping wedge 82 defines the iris 50 of the crimping mechanism 40. The travel block 84 of each jaw 44 is closely flanked by the annular disc 72 of the cam 62, and a small cam follower 86 extending axially inwardly from each block is inserted into the arcuate cam slot 80. Each cam follower 86 has a generally circular configuration and is angled in alignment with a tangent to the curve of the arcuate cam slot 80. Cam follower 86 is sized slightly smaller than the width of cam slot 80 and may be made of a lubricious material, such as nylon or teflon, to slide in the cam slot. A cam follower 86 is located at the radially outer extent of each travel block 84.

At this stage, further explanations regarding the materials are relevant. Many of the components are molded from a suitable polymer, such as the outer housing 42 and the cam 62. The lead screw 52, carriage 54 and of course the motor components are preferably metallic, but some may also be polymeric. The crimping jaws 44 may be a formed polymer, but it is desirable that the inner crimping wedge 82, which is in contact with the article being crimped, be a material having high strength and rigidity, as well as low friction, such as reinforced nylon. In this regard, the inner crimping wedge 82 may be an insert for the larger jaw 44. Also, as noted above, the cam follower 86 is preferably rigid and low friction, such as nylon. Of course, alternatives exist and these are merely exemplary materials.

It will thus be appreciated that rotation of cam 62 causes radially inward movement of crimper jaws 74 due to the interaction between arcuate cam slot 80 and cam follower 86. Fig. 7A and 7B are front views of the internal crimping mechanism 40 in both the open crimping jaw position and the closed crimping jaw position, showing the central cam 62 and the crimping jaws 44 assembled on the internal crimping mechanism. Only one arcuate cam slot 80 and one mating cam follower 86 on the jaw 44 are shown in phantom. It should be understood that although only one is shown each, there are two cam grooves 80 and two cam followers 86 associated with each jaw 44. The jaws 44 on which the cam followers 86 are shown are highlighted by extending the dashed lines along the respective angled edges to form angles a and β from the horizontal.

Figures 7A and 7B illustrate the lever arm 60 of the cam 62 being rotated in a Clockwise (CW) direction such that the cam follower 86 on each jaw 44 is exposed to the arcuate cam slot 80. Because cam slot 80 flexes radially inward as wheel 62 rotates clockwise, the radially inward cam force is transferred to cam follower 86. The inward movement of all of the jaws 44 from their rigid connection to their respective cam followers 86 is the same due to the sliding interaction between the jaws 44. It should be noted that the highlighted crimping jaws 44 maintain the same rotational orientation as they translate radially inward and downward. That is, the angles α and β describing the orientation of the jaws 44 relative to horizontal remain the same. The same is true for all jaws 44. As a result of this movement, the inner surface of the crimp wedge 82 defines a radially constricted iris 50. In addition, although the absolute angle of the tangent lines drawn relative to the curvature of the arcuate slot 80 varies from one end of the slot to the other, the orientation of the cam follower 86 remains parallel to these tangent lines due to the movement of the respective jaws 44. This facilitates sliding movement of the cam follower 86 within the slot 80.

Crimping jaws 44 have mating sliding surfaces such that they all move together in the same degree of translation as each other, albeit along different angles. In particular, each angled edge of the travel block 84 mates with an adjacent travel block edge in a tongue and groove manner. Referring back to fig. 5A and 5B, each travel block 84 has a slide rail 88 thereon that mates with an oppositely oriented slide rail on the travel block 84 on the adjacent jaw 44. This interaction can be seen in the perspective view of fig. 6. The sliding engagement of the rails 88 helps prevent binding between the jaws 44 as they move together inwardly.

In addition, the starting position of crimping the jaws 44 and the angle of the edge of travel block 84 causes the assembly of jaws to rotate as they cam inwardly (cammed). In essence, each crimping jaw slides inwardly relative to one of its adjacent crimping jaws, and the resulting displaced shape seen in fig. 7B is somewhat analogous to a windmill. The reader will also see from a comparison of fig. 7A and 7B that the projecting crimping jaws 44 translate radially inwardly and downwardly, equivalent to a clockwise rotation thereof.

As shown in fig. 5A-5C, the crimping jaws 44 also have linear guide slots 90 on the outer faces of the two travel blocks 84. These guide slots 90 interact with the above-mentioned cartesian guide elements 70, as will be described below. With particular reference to FIG. 5C, the guide slot 90 of each jaw 44 bisects the jaw angle θ.

Fig. 8 is a front view of the inner face of one half of the outer housing 42, showing the fixed guide channel 64. As described above, the guide channel 64 is tangential to the central aperture 48 in the housing 42. The guide channel 64 preferably comprises an axial recess in an outer plate 92 of the housing 42, wherein the housing half comprising the guide channel is desirably injection molded. The radially inner end of each guide channel 64 merges with an adjacent guide channel at about its midpoint. Because there are six guide channels 64 equally spaced and uniformly oriented around the orifice 48, the inner portions of the guide channels define the vertices of a hexagon that closely surrounds the orifice. Each guide channel 64 extends from the apex of the hexagon, beyond its point of tangency with the aperture 48, and outwardly to an outer edge 94 of the housing 48. The guide channel 64 interacts with a cartesian guide element 70 as will be described below. The number of guide channels depends on the number of jaws; i.e. half the number of jaws.

Fig. 9A shows a plurality of cartesian guide elements 70 arranged in space in the same manner as when interacting with the outer housing 42, fig. 9B shows separate individual cartesian guide elements 70, and fig. 10A and 10B superimpose the guide elements on the outer housing and channel 64. Each guide member 70 includes an angled, generally flat linear plate 96 having raised

linear bars

98a, 98b extending from opposite inner and outer faces of linear plate 96. The opposing

linear bars

98a, 98b are oriented perpendicular to each other and thus together define a right angle intersection, albeit on opposite faces of the guide element 70. The outer face of the guide element 70 abuts the outer plate of the housing 42 so that the outer linear bar 98a on that side fits snugly within the fixed guide channel 64. On the inner face, the guide member 70 contacts the assembly of crimping jaws 44, and the inner linear bar 98b fits snugly within the guide slot 90 on the six guide members. Because the outer linear bar 98a is constrained within the guide channel 64, the guide element 70 is also constrained to move linearly between a first position and a second position parallel to the guide channel.

Fig. 10A shows the position of the guide element 70 superimposed on the outer housing 42 when in the radially outward position (also in fig. 9A). As described above, the outer linear bar 98a extends within the guide channel 64 and is guided by the guide channel 64. In this starting position, the radially outer edges of the linear plates 96 are adjacent the outer edge 94 of the housing 42, and their radially inner edges are positioned just outside of the central aperture 48. Fig. 10B is a similar view showing guide element 70 in a radially inward position. The outer linear bar 98a slides inwardly along the guide channel 64 and the linear plates 96 fit closely together. The linear plates 96 define an irregular diamond shape having generally four vertices within the outer extent of the intersecting

linear bars

98a, 98 b. Straight sides extend between the vertices and there is a notch 100 on one side near one vertex. When the guide elements 70 are in their radially inward position, one apex in each guide element fits closely within the next notch 100, and in this way the nesting contact between all guide elements 70 provides a positive stop upon further inward movement of the crimping mechanism 40.

Fig. 11A and 11B are elevational views similar to fig. 7A and 7B with crimping jaw assembly 66 in place and showing cartesian guide members 70 interacting with crimping jaws 44. The guide members 70 are referred to as "cartesian" because of the opposing intersecting

linear bars

98a, 98b on each guide member. That is, as described above, the guide member 70 is constrained to move linearly along the guide channel 64 in the outer housing 42. At the same time, the interaction between the inner linear bar 98b on each member 70 and the guide slot 90 on each of the other crimping jaws 44 limits the movement of those jaws in the direction of the associated guide member 70.

Before discussing this coordinated movement, it should be noted that there are only six guide members 70, and twelve crimping jaws 44. Thus, as shown in FIG. 11A, each guide member 70 interacts with each of the other crimping jaws 44. The six crimping jaws 44a that interact with the guide member 70 may be referred to as guide jaws, while the six crimping jaws 44b that do not interact with the guide member are referred to as driven jaws. It is important to remember, however, that each crimper jaw 44 has a cam follower 86 thereon and, thus, is directly driven by cam 62.

Referring again to fig. 11A and 11C,

cartesian axes

102, 104 are superimposed on the guide member 70 and one assembly of its guide jaws 44 a. The first axis 102 extends along the outer linear bar 98a on the guide member 70. The reader will understand that the outer linear bar 98a interacts with the guide channel 64 on the non-illustrated half of the outer housing. Thus, the guide member 70 is constrained to move linearly along the first axis 102. The second axis 104 extends along an inner linear bar 98b on the guide member 70, the inner linear bar 98b corresponding to the guide slot 90 on the guide jaw 44 a. The second axis 104 translates with the guide member 70, remaining perpendicular to the first axis 102 at all times. Both the guide jaw 44a and the guide member 70 move together. This arrangement reduces frictional losses and allows for selective combination of the guide jaws 44 and the guide element 70.

Referring now to fig. 11B and 11D, cam 62 has been rotated clockwise causing sliding movement of all crimping jaws 44. As the guide jaw 44a begins to move inwardly, it is constrained to move along the first axis 102 with the corresponding guide member 70. Likewise, all six guide jaws 44 are constrained to move with their corresponding guide members 70. As each leading jaw 44a begins to move inwardly, it slides relative to one of the two adjacent trailing jaws 44 b. Of course, each driven jaw 44b is acted upon by two adjacent leading jaws 44 a. Due to the angled sides of the adjacent jaws 44, the assembly of jaws begins to rotate clockwise as explained above with reference to fig. 7A and 7B. The circumferential component of the motion of each guide jaw 44 transmits force through the guide slot 90 to the inner linear bar 98b on the guide member 70. This translates the guide member 70 along the first axis 102.

It should be mentioned that providing two sets of force actuators (disc 72, travel block 84 and guide member 70) results in a symmetrical balanced system and reduced stress. Of course, a single disc 72 and associated crimping element is possible, but a more robust design is desired.

As the guide member 70 and guide jaw 44a translate along the first axis 102, they continue to move inwardly relative to the outer housing 42. Of course, although they are not in direct contact with the guide member 70, the driven jaws 44b move in a similar manner as they are also acted upon by the cam 62 and come from the symmetrical and mating edge contact between the jaws. Fig. 11E isolates a center jaw of the guided crimping jaws 44a from fig. 11C and 11D and shows the absolute movement 106 of the jaws along the first axis 102. Continued rotation of the cam 62 eventually moves the crimping jaws 44 to the position shown in figures 7B and 11B. It is also noted that the tip of crimping wedge 82 on each jaw translates radially inwardly along radial line 110 through central crimping axis 46 (see fig. 11A). That is, compound motion 106 is parallel to a radial line 110 through curl axis 46. This ensures uniform crimping of the stent or valve.

Relative movement of the mating components in crimping mechanism 40 will occur whether or not an object is being crimped. However, when an object such as the expanded heart valve 20 of FIG. 1A is crimped, it exerts considerable resistance against the crimping mechanism 40. More specifically, the hoop strength of the expanded heart valve 20 provides a radially outward reaction force 108 directly to the crimping wedges 82 of the jaws 44, as shown in fig. 11E.

Without the guide member 70, the mechanism is unbalanced and the reaction force 108 will tend to rotate the jaws 44. Further, without the guide member 70, this reaction force would be translated by the crimping jaws 44 to the cam follower 86, and thus to the arcuate cam slot 80 of the cam 62. While the cam groove 80 is relatively robust, the cam follower 86 is not only susceptible to stress deformation, but is also susceptible to binding. However, due to the contact between the guide member 70, crimping jaws 44 and the fixed outer housing 42, the reaction force from the crimping process is transferred and distributed such that the stress on the cam follower 86 is reduced. In particular, the Cartesian guide members 70 absorb a substantial amount of stress and provide an effective fit for crimping the jaws 44. With respect to fig. 11E, the radially outward reaction force 108 from the crimping process is translated into a torque on the crimping jaws 44 a. This torque is resisted primarily by the rigid constraint imposed on the guide member 70 by the outer housing guide channel 64 to move along the first axis 102. More specifically, due to the interaction between the guide slot 90 and the inner linear rod 98b, the clockwise torque on the guide jaw 44a will translate directly to the respective guide member 70 and, due to the guide member 70 being rotationally fixed relative to the outer housing 42, this rotational torque is resisted by the guide member 70.

One benefit over previous crimpers is the smaller mechanism size (about 1/2 for the current crimper size) and the ability to operate at high crimping forces (small, rigid crimping jaws). The jaws 44 are displaced substantially radially using cartesian guide elements 70 located proximate the central aperture 46. This guided concept enables a significant reduction in the size of the crimping jaws 44 and an increase in the stiffness (or ability to withstand higher crimping forces) of the jaws. The radial alignment mechanism provided by the guide element 70 is based on a steep angular movement that translates into a radial force applied near the central crimping axis. The guide element 70 converts angular motion from the cam 62 into radial force by substantially separating the angular motion into cartesian motion. In this movement, the jaws 44 move radially similar to the previous crimper and the guide elements 70 move with them in the tangential housing channel 64.

In a preferred embodiment, the width of crimping mechanism 40 or the approximate diameter of cam 62 is about 80 mm. The overall height of crimping mechanism 40 (such as shown in fig. 2A, which includes cam 62 and associated actuator located above lead screw 52) is approximately 115 mm. Of course, these exemplary dimensions are for a mechanism capable of crimping a balloon-expandable prosthetic heart valve 20, such as shown in fig. 1A, to the delivery dimensions shown in fig. 1B. The mechanism must be robust enough to support the stainless steel support frame of the heart valve 20 from, for example, 30mm (D)_max) Compressed to 6mm (D)_min). A less rigid frame or a smaller size reduction may enable the size of the crimper to be further increasedShrinking, and conversely, greater size reduction may require a larger crimper.

Fig. 12A and 12B are schematic perspective views of an alternative embodiment of a crimping mechanism 120 in both an open position and a closed position of crimping jaws 122, respectively. The entire crimping mechanism 120 is not shown, but is similar to that shown in fig. 1-11. The primary difference in crimping mechanism 120 is the modification to guide member 124. That is, instead of having diamond plates with opposing intersecting linear bars as previously described, the guide members 124 are simple vertical bars attached together. The inner rod will extend within a guide slot 126 in the crimping jaws 122 and the outer rod will slide within a fixed guide channel in the outer housing (not shown). In all other respects, crimping mechanism 120 operates in the same manner as described above.

Fig. 13A-13C and 14A-14C illustrate another crimping mechanism 140 that is similar to that shown in fig. 1A-12B, but with fewer guide elements 142. The guide elements 142 are simple crossed linear rods, as described above with reference to fig. 12A and 12B. In addition, there are still twelve crimping jaws 144. However, compared to the previous embodiment, there are only two guide elements 142. Operation of crimping mechanism 140 as shown in figures 14A-14C is similar to that described above, wherein lead screw 146 rotates a cam (not shown) that initiates inward movement of crimping jaws 144. Since crimping jaws 144 are all connected in a tongue and groove fashion as described above, they will move in and out simultaneously even without guide member 142. Guide member 142 engages only two crimping jaws 144, but still provides a reduction in stress and a distributed application of force. Two guide elements 142 are considered to be the smallest and three, four or six are envisaged for a twelve-jawed mechanism. In the illustrated embodiment, the actual maximum number of guide elements 142 is six, or half the number of jaws. This allows the guide elements 142 not to interfere with each other as they slide back and forth.

Fig. 15A-15B schematically depict yet another crimping mechanism 160 of the present application that utilizes a compressible sleeve (e.g., a soft elastomer) rather than a plurality of separate jaws. Fig. 16A-16B are front views of crimping mechanism 160 with the front cover removed to show the internal components in the position of fig. 15A and 15B, respectively. Crimping mechanism 160 features a cam 162 that rotates within a pair of end plates 164 (only one shown). The end plate 164 is secured to a housing 166, and an actuating mechanism, much like the lead screw assembly described above, is disposed within the housing 166.

A compressible sleeve 168 is rotationally retained between the end plates 164 and includes an annular elastomeric sleeve having an outer axial groove. As shown in fig. 15B and 16B, the lumen or orifice 170 defined by the sleeve 168 contracts to a smaller sized orifice 170' upon rotation of the cam 162.

Referring to fig. 16A-16B and 17-19B, a plurality of link plates 172 are arranged for coordinated movement within the cam 162. More specifically, the outer ends 174 of the plates 172 are journaled for rotation in respective holes 180 around the outer periphery of the cam 162. The cam 162 may have a short section of gear teeth 176 on its lower edge that can be engaged by a rack, lead screw or other such transmission within the moving housing 166.

Fig. 17 shows crimping mechanism 160 exploded. The array 182 of link plates 172 and mating compression plates 178 (see fig. 19A-19B) includes at least 12 and preferably at least 24 connecting plates. The array 182 is disposed within the cam 162, and the cam 162 includes two series of peripheral holes 180 within which the two outer ends 174 of each link plate 172 are journaled for rotation. In this way, the symmetry reduces any possible misalignment forces during crimping of the prosthetic heart valve. Each end plate 164 has a central aperture through which the prosthetic heart valve passes into the middle of the crimping mechanism 160, and an array of radial slots 186, which will be described below.

As best shown in the cross-sectional views of fig. 19A-19B, each link plate 172 is hinged on an inner end to a compression plate 178. The inner end of each compression plate 178 engages one of the axially-oriented grooves 179 around the outside of the compressible sleeve 168. Compression plate 178 is formed with two outer tracks 188 that slide within radial slots 186 formed in end plate 164. Rotation of the cam 162 displaces the outer ends 174 of the link plates 172 so that they transition from the angled orientation shown in fig. 16A to the radial orientation in fig. 16B. Because the inner end of link plate 172 is hinged to compression plate 178, compression plate 178 is urged radially inward. The engagement between the outer track 188 and the slot 186 constrains the compression plate 178 for radial movement.

Webs

172, 178 around sleeve 168 thus push inwardly on groove 179 and radially compress the sleeve to reduce the central bore diameter.

While crimping mechanism 160 represents a superior solution, in which a single crimping "jaw" reduces the number of moving parts and associated friction, the size of the crimp is limited and may require a series of similar crimpers to reduce the size of the article in stages. Of course, if only a small amount of crimping is required, one crimping mechanism would be appropriate.

Fig. 20A-20C are perspective and cross-sectional views of multi-stage crimper 200 wherein outer housing 202 is wrapped around a series of progressively larger sized crimping

mechanisms

204a, 204b, 204C, each having compressible "jaws". The crimping

apertures

206a, 206b, 206c for the three crimping mechanisms gradually reduce the size of a prosthetic device, such as the prosthetic heart valve described above. Fig. 20B shows the front cover of housing 202 removed to show one rotating cam 210 on the smallest crimping mechanism 204 a. The lower section of the gear teeth 212 on the cam 210 may be acted upon by a linearly displaced rack 214 to rotate the cam. Although not shown, a larger crimping mechanism may also have similar cams that are simultaneously acted upon by a single rack 214. Fig. 20C shows the front of the cam 210 removed to expose a plurality of connection plates 216, which connection plates 216 may be the same as those described above with respect to fig. 15-19.

To crimp the prosthesis, it is first placed in the largest crimping mechanism 204c and the rack 214 is displaced to reduce the size of the prosthesis by a first amount. The rack 214 returns to its original position and the prosthesis is then transferred to the intermediate crimping mechanism 204b and its size is further reduced. Finally, the smallest crimping mechanism 204a reduces the size of the prosthesis to its final diameter. Although three crimping mechanisms are shown, a minimum of two stages and more than three stages may be used to sequentially crimp the prosthesis in this manner.

Fig. 21A-21B schematically depict yet another crimping mechanism of the present application that utilizes compressible jaws 260 (e.g., a soft elastomer). The jaws 260 are positioned between a series of spoke-like plates 262, the spoke-like plates 262 being initially angled radially so as to be nearly tangent to a circle defined by an inner face 264 of each compressible jaw 260. The outer faces 266 of each jaw 260 are constrained such that they cannot expand radially outwardly. By rotating all of the spoke-like plates 262 together (as shown in FIG. 21B), the compressible jaws 260 are squeezed by the reduction in volume between the plates 262, causing them to expand inwardly. The aggregation of all of the interfaces 264 defines a curled iris and compresses any items therein. Again, for compressible jaws, the magnitude of the crimp is limited and a series of similar crimpers may be used to reduce the size of the article in stages, as described above with respect to fig. 20A-20C. Of course, if only a small amount of crimping is required, a single crimping mechanism would be suitable.

It should be understood that the internal components of the crimping mechanisms described herein may be formed from a plurality of separate connected components, or by combining some of these components in a unitary member. For example, the six guide jaws 44 seen in fig. 11A and 11B are constrained to move with their respective guide members 70, so these components may be formed as a single piece. Rather, some elements can be separated into more than one piece, such as jaws, for ease of manufacture. The latter case is illustrated by the crimping mechanism shown in fig. 22A-22C.

Fig. 22A is a perspective view of an alternative crimping mechanism 300, the crimping mechanism 300 having a modified actuating mechanism and outer housing 302 shown in phantom. Fig. 22B shows crimping mechanism 300 from a different perspective and without housing 302, and fig. 22C shows a number of internal components including an exploded inner crimping wedge 306.

The modified actuating mechanism is characterized in that it has a relatively large diameter horizontally oriented lead screw 310, which lead screw 310 is journalled for rotation on either side of the housing 302 and perpendicular to the horizontal crimping axis. A motor 312 in the lower portion of the housing 302 is desirably connected through a power transmission (e.g., a gear or pulley 314) to drive the lead screw 310. In contrast to the actuation mechanism described above with respect to fig. 2A-2B, rotation of the lead screw 310 results in translation of the carriage assembly 316, the carriage assembly 316 being connected to the cam 318 by a link arm 320. That is, the link arm 320 is journaled for rotation at opposite ends, one on the carriage assembly 316 and one on the outer lever arm 322 of the cam 318. As with the previous embodiment, the cam 318 has two spaced apart discs 324, each having a lever arm 322, and two link arms 320, one driving each lever arm. This provides an extremely balanced and robust drive system that prevents binding of the movable jaw members.

This linkage arrangement provides an extended actuator arm that generates a higher torque (linear translation to radial) at the end of the crimping process where the greatest force is required. In other words, a stented prosthetic valve is more easily crimped at its larger diameter and becomes stiffer as it contracts. When the carriage assembly 316 reaches the end of the lead screw 310, each rotation of the link arm 320 relative to the lead screw applies a large amount of torque to the cam 318.

Figure 22C is an exploded view of the components of the combination cam 318 and jaw mechanism. Crimping wedges 306 are shown arranged in a generally helical array because they will be retained within central opening 330 in cam 318. Crimping wedge 306 replaces the inner crimping wedge 82 of the jaws 44 described above with respect to figures 1A-11E. Flanking each side of the cam 318 is a set of six generally triangular (disk-shaped) travel blocks 332 and six guide blocks 334 in combination. The guide block 334 basically comprises two back-to-back parts: an inner travel block 336 similar to the travel block 332 and an outer guide element 338 similar to the cartesian guide element 70 described above. As shown in FIG. 22B, six travel blocks 332 and six guide blocks 334 engage in the same manner as the jaws 44 of FIGS. 1A-11E. The guide element 338 has a linear bar 340, the linear bar 340 sliding within a fixed guide channel (not shown) in the inner face of the housing 302. Each of the disc-shaped traveling blocks 332, 336 engages with the adjacent blocks in a tongue-and-groove manner to achieve smooth sliding movement therebetween.

A crimping jaw assembly of crimping wedge 306, six traveling blocks 332 and six guide blocks 334 is formed by a plurality of aligned through holes and bolts 342. As in the earlier version, the helical cam slot 350 in the cam 318 moves the small cam pin 352 inwardly as the wheel rotates. The cam pin is retained within a hole (not shown) on the inner face of each of the six travel blocks 332 and the six guide blocks 334 such that the blocks are urged along a linear path constrained by a linear bar 340 sliding within a fixed guide channel of the housing 302. This is the same as described above. The end result is that the inner tip of crimping wedge 306 translates radially inward to uniformly crimp the stented valve therein.

Each crimping jaw itself comprises a combination of one of crimping wedges 306 connected at both axial ends to a pair of travel blocks 332 or a pair of guide blocks 334. It will be appreciated that several components may be separately fabricated from the same or different materials and then passed over the cam 318 via the bolt 342 and secured together by the cam 318. Preferably, crimping wedge 306 is formed from a relatively rigid metal, or only the inner tip of crimping wedge 306 may be metal. The sliding member may be metal or hard plastic or resin.

The previously separated components combined to form six guide blocks 334 illustrates the option of using fewer, more complex components, while the exploded assembly of fig. 22C illustrates the option of using more, less complex components. Ultimately, which configuration is selected depends on the materials, mold cost, engineering difficulties, and the like. In the preferred embodiment, the assembly comprising the wedge 306 plus the two travel blocks 332 or the two guide blocks 334 is formed as one piece, preferably defining twelve jaw assemblies.

The exemplary embodiments of the present invention have been described, but the present invention is not limited to these embodiments. Various modifications may be made without departing from the scope of the subject matter of the present invention as read by the appended claims, the description of the invention and the accompanying drawings.

Claims

1. A crimping device, comprising:

a plurality of crimping jaws (44, 44a, 44b, 122, 144) in meshing engagement and circumferentially arranged about a crimping aperture (48) having a central crimping axis (46), each said crimping jaw having an inner crimping wedge (82, 306);

a rotating cam (62, 318) adapted to act on said crimping jaws (44, 44a, 44b, 122, 144) and displace them substantially radially inwards;

a stationary outer housing (42, 302) containing the crimping jaws (44, 44a, 44b, 122, 144); and

a plurality of guide elements (70, 142, 338) each constrained by a fixed groove (64) in the outer housing (42, 302) to move (106) between a first position and a second position along a tangent line (102) tangent to a circle about the central crimping axis (46), the guide elements (70, 142, 338) moving at least some of the crimping jaws (44, 44a, 44b, 122, 144) along the tangent line (102) such that all of the crimping wedges (82, 306) of the crimping jaws (44, 44a, 44b, 122, 144) translate inwardly along radial lines (110) toward the central crimping axis (46),

wherein the stationary outer housing (42, 302) further comprises the rotating cam (62, 318) and the crimping jaws (44, 44a, 44b, 122, 144) are assembled on the rotating cam (62, 318).

2. The device of claim 1, wherein said crimping wedge (82, 306) is made of a different material than the remaining crimping jaws (44, 44a, 44b, 122, 144).

3. The device of claim 1, wherein the guide element (70, 142, 338) is a separate element from the crimping jaws (44, 44a, 44b, 122, 144).

4. The device of claim 1, wherein the guide element (70, 142, 338) is rigidly coupled to the at least some of the crimping jaws (44, 44a, 44b, 122, 144).

5. The device of claim 4, wherein the guide element (338) is integrally formed with the at least some of the crimping jaws (44, 44a, 44b, 122, 144).

6. The device of claim 4, wherein the guide elements (70, 142, 338) are secured to the at least some of the crimping jaws (44, 44a, 44b, 122, 144).

7. The device of any one of claims 1-6, wherein each of said crimping jaws (44, 44a, 44 b) comprises a combination of a pair of travel blocks (84, 336) on a side of said rotating cam (62, 318) and one of said crimping wedges (82, 306) extending beyond a central aperture (48) in said rotating cam (62, 318).

8. The apparatus of claim 7 wherein the rotary cam (62, 318) comprises two cam disks (72, 324) with helical cam slots (80, 350) that act on cams fixed to each laterally traveling block (84, 336) and extending axially inward into the cam slots (80, 350).

9. The apparatus of claim 8 wherein the cam disks (72, 324) each have a cam rod (60, 322) extending radially outward therefrom, the cam rods being driven by a carriage assembly (54, 316) on a lead screw (52, 310).

10. The device of claim 9, further comprising a drive motor (312) for actuating the lead screw (310).

11. The apparatus of any of claims 9 or 10, further comprising a link (320) between the cam lever (322) and the carriage assembly (316), the link (320) increasing the torque applied to the rotating cam (62, 318) when the carriage assembly (316) reaches opposite ends of the lead screw (310).

12. Device according to any one of claims 1-6, wherein half the number of guide elements (70, 142, 338) act as crimping jaws (44, 44a, 44b, 122, 144), such that some of the crimping jaws (44, 44a, 44b, 122, 144) are driven and others are followers.

13. The device according to any one of claims 1-6, wherein each of said guide elements (70) comprises an irregular diamond shaped linear plate (96) having four vertices and a straight edge therebetween, with a notch (100) on a side adjacent one of said vertices, and one of said vertices of each said linear plate fits closely within said notch (100) on an adjacent guide element (70) when said guide element (70) is displaced along said tangent line (102) to said second position, and this manner of nested contact between all said guide elements (70) provides a positive stop for further inward movement (106) of said crimping jaws (44, 44a, 44b, 122, 144).